Almost all modern CPUs use Speculative Execution as a means to improve performance and efficiency. Your computer’s processor performs tons of calculations in advance and chooses the correct one according to a program’s flow. It makes sense as an idle CPU is undoubtedly a wasted resource.
When it comes to Linux creator Linus Torvalds, he likes the way speculative execution improves performance. What irritates him is the fact that not all incorrect calculations are completely discarded — this is what turned out to be the root cause of bugs like Spectre and Meltdown.
Linus expressed these views during The Linux Foundation’s Open Source Summit (Via: ZDNet) in Vancouver. The fact that the developers of operating systems and kernel developers had to manage the fixes is something that irks him a lot.
“It’s not fair. When we screw up, it’s fair, we have to fix it. But it feels less fair when we have to fix someone’s else’s problems,” he added.
What made things worse was the fact that Intel kept things hidden and didn’t allow different distro maintainers to talk to each other.
At the conference, Greg Kroah-Hartman, the stable Linux kernel maintainer, further said: “We yelled at [Intel] and pleaded, and we finally got them to allow us to talk to each other the last week of December.
“All of our Christmas vacations were ruined. Intel messed up.”
Interestingly, these bugs resulted in a new kind of collaboration between Linux and Windows developers. “We now have this wonderful back channel. We’re talking to each other and we’re fixing bugs for each other,” Kroah-Hartman added.
Overall, Torvalds accepts that things have changed a bit and Intel has gotten much better. When the latest Foreshadow bug was spotted, Intel notified the Linux kernel devs on time.